1. Field of the Invention
The present invention relates to disc brake assemblies, and more particularly to a floating brake rotor assembly in which the connecting pins are not subject to torque forces transferred from the brake rotor to the hub.
2. Description of the Related Art
Various designs for floating brake rotor assemblies have been proposed. Examples of such designs are provided by U.S. Pat. No. 4,848,521, issued Jul. 18, 1989 to Z. Izumine; U.S. Pat. No. 5,520,269, issued May 28, 1996 to S. Yamamoto et al.; U.S. Pat. No. 5,921,633, issued Jul. 13, 1999 to P. Neibling et al.; U.S. Pat. No. 6,267,210, issued Jul. 31, 2001 to D. L. Burgoon et al.; U.S. Pat. No. 6,305,510, issued Oct. 23, 2001 to K. J. Bunker; and U.S. Pat. No. 6,374,956, issued Apr. 23, 2002 to E. Naeumann et al.
In general, a floating brake rotor assembly is comprised of a brake rotor and a hub. The brake rotor is annular with two flat sides that provide surfaces to which brake pads can be applied. The hub provides a means for mounting the brake rotor to the wheel of a vehicle. The two sections are interconnected in a manner that allows the brake rotor to move, or “float,” axially relative to the hub. One of the main advantages of a floating rotor is that binding of the rotor with a brake pad, due to heat distortion of the rotor, is minimized or avoided. Hence, as the rotor warps slightly due to thermal expansion, it floats relative to the brake pad.
Typically, the brake rotor and the hub are interconnected in one of two manners. In one manner, as taught by Yamamoto et al., and particularly referring to FIG. 1 thereof, the inner aspect of the brake rotor and the outer aspect of the hub have mating semi-circular indentations that form apertures through which a pin is passed to connect the rotor and hub. In the other manner, as taught by Burgoon et al., and particularly referring to FIG. 4 thereof, overlapping portions of the brake rotor and the hub have mating apertures that align to form a single continuous aperture through which a pin or bolt is passed.
Significantly, in each of the aforementioned manners for interconnecting a brake rotor and a hub, the load transfer between the two components is transferred solely across the connecting pins. Consequently, several known problems are associated with each manner. First, because load thrust transfer must occur across a relatively small surface area, localized wear and deformation of the brake rotor, hub and pins occur frequently. Second, the maximum load transfer between the brake rotor and the hub is constrained by the load capacity of the pins. Third, thermal transfer capacity from the brake rotor to the hub is constrained, thereby lessening heat dissipation and increasing the likelihood of thermal induced distortion of the brake rotor.
U.S. Pat. No. 4,848,521, issued to Z. Izumine; U.S. Pat. No. 5,921,633, issued to P. Neibling et al.; and U.S. Pat. No. 6,267,210, issued to Burgoon et al. each teach a rotor and hub assembly wherein the rotor and hub are connected by a number of pins that pass through apertures in overlapping portions of the rotor and the hub, with the pins being oriented parallel to the axis of rotation. As discussed above, this configuration results in the entire load transfer between the rotor and hub being transferred via the pins and further results in the aforementioned problems.
On the other hand, U.S. Pat. No. 5,520,269, issued to S. Yamamoto et al., and U.S. Pat. No. 6,305,510, issued to K. J. Bunker, each teach a rotor and hub assembly wherein corresponding semicircular indentations along the inner edge of the rotor and the outer edge of the hub mate to form apertures through which pins secure the rotor and hub together. However, this configuration also results in the entire load transfer between the rotor and hub being transferred via the pins. Additionally, Bunker uses a combined pin and leaf spring, which complicates assembly and replacement of the rotor.
U.S. Pat. No. 6,374,956, issued to E. Naeumann et al., teaches a brake rotor and hub assembly wherein the rotor and hub are connected in a non-coplanar configuration with an insulating layer between the two components. However, due to lateral torque forces, the non-coplanar configuration of the rotor and hub is more prone to produce warping and excessive wear.
U.K. Pat App. No. 2,150,263, published on Jun. 26, 1985, depicts a rotor and hub assembly wherein the rotor and hub are interconnected by a spring. The spring is planar and is disposed in a groove on the outer edge of the hub such that when a pin is passed though a shaft that intersects the groove, the ends of the spring extend into recessed areas on the inner edge of the rotor. This configuration requires precise placement of the spring groove, pin shaft, and recessed areas, and thus complicates manufacture, assembly and replacement of the components.
Consequently, none of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed. Thus, a floating brake rotor assembly solving the aforementioned problems is desired.